American Citizen UAE Visa Requirements (Muscat)

Can any American Citizen verify that in travelling from Muscat to Dubai by auto we do not need to have gone through the e-visa online process expected by certain other GCC residents. UAE Embassy Washington suggests no visa required even US citizens "with visas or entry stamps from other countries". But that may be different from Oman Residence Card holders. UAE Embassy Muscat says not need for the visa. But since this would be my first trip I'd like to hear reassuring words from another American citizen.